class Solution {
public:
    uint32_t reverseBits(uint32_t n) {
        uint32_t ans = 0;
        for (int i = 0; i < 32; i++) {
            if ((n >> i) & 1) {
                ans |= (1 << (32 - i - 1));
            }
        }
        return ans;
    }
};